1. Field of the Invention
The present invention relates to the field of network management, and more particularly to processes for determining whether two communicating network drivers are directly connected across a physical link.
2. Background of the Invention
In the management of data networks, it is often desirable to understand the topology of the network, including whether there are direct links between particular devices in the network, the nature of the network intermediate devices which interconnect links or end stations on the network, and the capabilities of individual end stations on particular links. Thus, network management stations often maintain a topology map for the network to assist an administrator in the management of the network. A variety of techniques has been developed for automatically discovering the topology of the network to further automate the management of networks. See for example U.S. Pat. No. 5,421,024 entitled DETECTION OF A RELATIVE LOCATION OF A NETWORK DEVICE USING A MULTICAST PACKET PROCESSED ONLY BY HUBS invented by Faulk, Jr., et al.; see also, U.S. Pat. No. 5,293,635 entitled DETECTION ON A NETWORK BY A MAPPING APPLICATION OF A RELATIVE LOCATION OF A FIRST DEVICE TO A SECOND DEVICE invented by Faulk, Jr., et al.; U.S. Pat. No. 5,048,009 entitled BROADCAST STATION LOCATOR FOR A LOCAL AREA NETWORK invented by Conrad; and U.S. Pat. No. 5,226,120 entitled APPARATUS AND METHOD FOR MONITORING THE STATUS OF A LOCAL AREA NETWORK invented by Brown, et al.
Networks include intermediate devices which interconnect end stations and manage data flow among end stations and ports. Often, these intermediate devices are transparent to drivers running in the end stations or ports they interconnect. Thus, it is often difficult to determine whether there are intermediate devices between two communicating end points. Furthermore, it is often desirable to optimize performance of communication between communicating end stations which have drivers that are capable of certain classes of functions. Thus, automatic negotiation techniques have developed by which end points in a network negotiate the communication technique to be utilized between the end points. In these settings, it is sometimes important to ensure that there are no intervening devices between the devices negotiating the processes to be executed, which might not be able to operate under the ultimately negotiated process.
Thus, it is desirable to provide a technique which is capable of automatically determining whether there is a direct link between communicating end points on a network. Such a technique would be useful in systems which allow for automatic negotiation of network capabilities between communicating end stations, and in networks including automatic topology mapping techniques.